Means for supplying powdered fuel to furnaces



June 19, 1928.

. R. SMITH MEANS -FOR SPPLYING POWDERED FUEL TO FURNACES Filed e t. 22, 1925 Illu YPatented June 19, 1928.

' UNITED STATES PATENT OFFICE.

ARTHUR R. SMITH, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC i COMPANY, A CORPORATION OF NEVI YORK.

MEANS FOR SUPPLYING POWDERED FUEL TO FURNACES.

Application Afiled September 22, 1925.

rThe present invention relates to the feeding of pulverized fuel to furnaces, the fuel ordinarily used being pulverized coal.

The object of my invention is to provide an improved method of and means for feeding pulverized fuel to furnaces which gives a uniform mixture of the fuel and air and an even distributionfof the fuel and air to the several burners of the furnaces, and for a consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto.

In the drawing Fig. 1 is a vertical sectional view of a. fuel and air .distributor embodying my invention; Fig. 2 is a top plan view thereof, parts being broken away in .order to better illustrate the structure; Fig.

3 is a detail sectional view on an enlarged scale taken on line 3 3, Fig. 1; and Fig. 4

is a side elevation of the distributor illustrating its connection to furnaces.

In carrying out my invention, I utilize a powdered fuel and air mixture, the mixture havingbeen formed in any suitable manner, and I provide a device for divi-ding upthe mixture and apportioning it among the several burners of the furnaces. Heretofore it has been thecustom, so far as I am aware, to distribute thefuel Vfrom the bins by means of screw feeders, the primary air being injected into the fuel after it leaves the screws. In other words, the fuel has been measured out for each individual burner and the primaryjair then added to it. According to my invention Imixthe air and fuel first and then apportion' it among the several furnaces. By this means I amenabled to obtain a more uniform mixture of the fuel and air and a more even distribution of it than has been obtained heretofore.

Referring lto Ythe drawing, 5 indicates a casing which may be supported in any suitable manner and at anyA desired point. Connected yto the top of the casing is a conduit 6 through which a mixture of fuel and air, forexample, powdered coal and air is supplied to the casing. The powdered coal and air maybe mixed in any suitable Way and by means of any suitable apparatus, the mixture supplied being the. pulverized` fuel mixed with the primary air. Fixed to the lower end of casing() is a struct-ure which provides a bottom for the casing comprising a reentrant portion 7 and an angularly exment integral with each valve 11.

Serial No. 57,807.

tending wall 8 having a series of circumferentially spaced passages or openings 9 therein. The upper portion of the structure comprises walls which provide an annular housing 1() surrounding the lower portion Aof casing' Each passage 9 is provided with a valve 11 by means of which it may be covered and uncovered. The valves lie against the inner surface of wall 8 and at their upper portions are provided with vertically extending parts 12 having gear teeth 13 thereon. This forms a gear seg- Resting on top of parts 12 is a ring gear 14 having teeth 15 on its outer surface. In annular housing 1() and adjacent to each valve 11 is a pinion 16 carried by a stem 17 which projects out through housing 10 and has a knob 18 on its end. Between knob 18 and the top wall of housing 10 is a spring 19A which serves normally to hold pinion 16 into engagement with the top wall of housing 10. .Pinions 16 are of a width such that normally they mesh with both the gear teeth on parts 12 and ring gear 14. With this arrangement, when any one of the pinions 16 is turned, it `turns its valve 11 and also the ring gear 14 which in turn serves to turn allV the other valves 11 by reason of the connection between the pinions and the ring gear. On the other hand, when it is desired to adjust a valve 11 individually, then the particular pinion 16 may be pushed downward out of mesh with ring gear 14 so that when it is turned it moves only its valve 11. By this means it will be seen that any one of the valves may be adjusted individually or all the valves may adjusted Simultaneously.

Below wall 7 is an outer wall 20 provided with a plurality of projections 21 which form discharge chambers 22, there being a .discharge chamber for each opening 9.

Leading from each discharge chamber 22 is a. discharge conduit 23 which leads to a burner of a furnace. In Fig. 4, 24 indicates a furnace and 25 a burner. It will be understood that each conduit Q3 leads to a burner 'eonnected to a furnace, such as the furnace 24. vIn the present instance six conduits Q3 are shown and each would lead to its own burner. However', this number of conduits is shown only by way of example and any suitabie number of discharge conduits may be provided.

Discharge chambers 22 are large at the end into which the conduit y23V is connected and gradually converge inward toward wall .8. This is shown best in Fig. 2 of the draw-V ing.` f

27 is a worm wheel 28 mounted on ashaft 29. Shaft 29 is carried by a step bearing 30 iu the bottom wall of casing 27 and by a bearingV 31 carried by wall 7. Meshing with worinwheel 28 is a pinion 32 driven by a suitable electric mo'tor 33. iittached to shaft29 is an iinpeller wheel or blower wheel 34 provided 'with buckets or vanes 35 which stanti directly beneath wall 8 and revolve iii proximity thereto, the buckets or if'anes lying between the Vouter surface of Vwall Y8 and chambers22. This impellerwheel or blower "wheel-serves to Italie 'the mixture of fuel 'from casing land discharge it to the i'e- Yspectii-fe chambers 22. 85 is a conduit which ServesV to tahematerial which leaks Lto a point around vshaft 29 and convey it back to 'casing 5 adjacent to the inlet side of the blower wheel vanes. The walls which form discharge chambers 22 are one continuous structure'and at eacliend of the c'nanibers they extend into close proximity to the discharge edgesof vane Vring 35. There is thus formed, in substance, a seriesfof circumferen'tially spaced pockets, one adjacent to each l opening oi vpassage 9, and each separate from the others. y

yWith the above described arrangement,

Vwhen Vmotor 33 is ruiming,v driving the .biowerwheel 34, the buckets or vanes `35., as

they .pass eacli'individual -opening 9, suck fuel andairfroni casing and discharge it to Ythe adjaoentchaniber22. As the yblower wheel revolves, therefore,Y there will be a continuous flow of air and Afuel through each opening 9 to the chamber 22 with'which it communicates. If the valves 11 are .all open .to the same extent, then theainount .of fuel and airdischarged to each chamber will be the lsanie.' If Vit is desired yto vary. the

amount of fuel supplied to all the chambers `22 in.thejsameproportiomjall'the valves ll maybe operated.simultaneously.to adjust .the

Lfthe various valves l1 are set-differentlyin accordance with the `requiremeiits of the different burners, then. when all areadjusted siinul Vtaneously. they'will be charged in proportionate amounts. vairrangement shown, l

Instead of'u'singthe valve mayV use any other suitable arrangement. for accomplishing the ydesired result. For example, in adjusting theY valves individually the width of the Supported by wall 20 is a frame 26 onV Vwhich is'supported a easing 27. In casing YLev/alma openings may be reduced radiallyv while in adjusting the valves simultaneously the widths may be reduced circumferent-ially.

The impeller wheel or blower wheel .serves toV a considerable extent to mix the fuel and air and to discharge an even mixture to each` Y of the chambers 22. Also it functions to apportionV the mixture in the described manner among the several chambers. By my invention therefore, l ain enabled to supply pulverized fuel and primary air to a number of burners in the desired amounts.` At the Asame time I can easily vary and adjusttlie mixture supplied to all'the burners or to any individual burner. j My invention has Ythe advantage, also,

that the casing 5 may Vbe located .at any desiied point and be connected to thev furnaces Y,

by relatively small pipes. v Y

Yln accordance with theV provisions of the patentstatute's, I have described the princi-4 ple of operation of my'invention, together with the apparatus which I now considerato vrepresent the 'best embodiment thereof,'but

Ti desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out'by other means. VWhat Iclaiin as new'an'd desire to secure f ci;

by Letters Patent of the United States is j l. The combination [witha plurality Yof pulverized fuel burners, of a bin, means through which pulverized fuel and air mixture 'may `be supplied 'to said `vbin, conduits leading from the lower end of Vsaid'bin `to lsaid burners, a vertical shaft projecting into said'bin, a centrifugal blower iinsaid `bin carried by -said vertical shaft, and vmeans providing passages 'for' conveying "fuel 4and aii'` mixture. from VsaidV blower to' said .con-

duits.

2.V 'The Vcombination with a `.plurality rof a pul'verized fuel burners, of a bin, means through .which pulverized fuel and air mix-I .turemay be supplied to Vsaid bin,- conduits leading from the lower end of said lbin to Vnu said burners, a vertical shaftprojecting into saidbin, a centrifugal blower in said bin carried by said vertical shaft, meanspro- `viding passages for conveying fuel andy air mixture from said blower vto said conduits, and means located in the bin forregulatingthe amount lof mixture supplied by YtheV blower tothe respective passages. Y

arie .Combination with 'a piufaiay aiV .fuel'.burners, of a bin,- meansthrough 'which pulverized fuel and alirf mixture vmay be sup- ;plied to the bin, a series of spaced discharge chambers surrounding the bin, conduits connectingthe chambers tothe burners, spaced passages connecting Vthe bin to said chain- .beis and a centrifugal blower fordischarg ying. fuel and air mixture fromV the V.bin

through said passages to'y said'V discharge chambers.

The combination with a plurality o'f pulverized fuel burners, of a bin, means through which pulverized fuel and air mixture may be supplied to said bin, conduits leading from the lower peripheral portion of said bin to said burners, a vertical shaft projecting into said bin, a centrifugal blower in said bin carried by said sha-ft, means providing passages for conveying fuel and air mixture from said blower to said conduits, and a valve in the bin for regulating the amount of air and fuel mixture supplied to each passage.

5. A distributor for a mixture of fuel and air comprising a casing, a series of discharge chambers surrounding the casing, a conduit connected to each discharge chamber, spaced passages connecting the casing to said chambers, an impeller wheel for discharging fuel and air mixture from the casing through said passages to said discharge chamber, and valve means for adjusting the area. of said passages. p

6. A distributor for a mixture of fuel and air comprising a casing, a series of discharge chambers surrounding the casing, a conduit connected to each discharge chamber, spaced passages connecting the casing to said chambers, an impeller wheel for discharging fuel and air mixture from the casing through said passages to said discharge chamber, a

valve controlling each passage, and means for adjusting said valves either individually or simultaneously.

7. A distributor for a mixture of fuel and air comprising a casing having a series of circumferentially-spaced discharge openings at its lower end, means within the casing for directing a fuel and air mixture toward said openings, a centrifugal blower the blades of which rotate past said openings for effecting passage of fuel and air mixture through the openings, and discharge corrduits to which fuel and air mixture isidelivered by said centrifugal blower.

8. A distributor for a mixture of fuel and air comprising' a casing having a` series of circumferentially spaced discharge openings at its lower end, mea-ns within the casing for directing a fuel and air mixture toward .said openings, a vertical shaft projecting into the casing, a centrifugal blower carried by said shaft, the blades of said blower rotating past said openings for effecting passage of fuel and air mixture through said openings, and discharge conduits to which fuel and air mixture is delivered by said centrifugal blower.

ln witness whereof I have hereunto' set my hand this 19th day of September 1925.

ARTHUR R. SMITH. 

